磁场对纳米MnZn铁氧体前驱体形貌的影响

Effect of Magnetic Field on the Morphology of Nano-MnZn Ferrite Precursor

摘要:

采用SEM，XRD，TEM，TG等手段研究了磁场对共沉淀法制备纳米MnZn铁氧体前驱体形貌及晶态结构的影响。结果表明，随着磁感应强度增大并达到某一临界值时，纳米颗粒形貌由球状向链状转变，继续增加磁感应强度将获得针状、棒状或纤维状的颗粒，10T强磁场下获得棒状颗粒呈现单晶结构。热重分析表明10T磁场下获得的纳米颗粒由于单维尺寸增加而导致活性降低。根据晶体生长理论，讨论了磁场影响纳米颗粒形核和长大过程的机理。

Abstract:

Effect of magnetic field on the shape and crystalstructure of nano MnZn ferrite precursor prepared by co-precipitation way was studied by using SEM, XRD, TEM and TG. It was shown that the morphology of nano particles would change from spheric to chain-like with increasing the magnetic field to a certain critical value. The claviform-like nano particles obtained in a magnetic field of 10 T showed the structure information of single crystal. Thermal gravity curve revealed that the activity of nano particles was reduced in a magnetic field of 10 T due to the increase of one dimension size. The mechanism of magnetic field effect on the nano particle nucleation and growth was discussed by crystal growth theory.